<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>03_css常用值</title>
    <style>
        h1{
            color: red;
            color:rgb(255,0,0);
            color: rgba(0,255,0);
            color:rgb(0,0,255);
            color:rgb(255,255,0);
            color:rgb(255,0,255);
            color:rgb(0,255,255);
            color:rgb(0,0,0);
            color:rgb(128,128,128);
            color:rgb(255,255,255);
            color:#FF0000;
            color:#00FF00;
            color:#0000FF;
            color:#00F;
            color:#F00;
            color:#0F0;
            color:#000;

        }
        div {
            width:100px;
            height:100px;
            border:5px solid #000;
         }
        .d1 {
            background-color:rgb(255,0,0,1);
        }
        .d2 {
            background-color:rgb(255,0,0,0.7);
        }
        .d3 {
            background-color:rgb(255,0,0,0.5);
        }
        .d4 {
            background-color:rgb(255,0,0,0.3);
        }
        .d5 {
            background-color:rgb(255,0,0,0);
        }
        .bgi {
            width : 100px;
            height:100px;
            background-image: linear-gradient(45deg, red, yellow, blue, green);
        }
        .viewport {
            width: 100vw;
            height: 100vh;
            background-color: yellow;
        }

    </style>
</head>
<body>
    <div class="viewport"></div>
    <h1>测试色值</h1>
    <div class="d1"></div>
    <div class="d2"></div>
    <div class="d3"></div>
    <div class="d4"></div>
    <div class="d5"></div>
    <div class="bgi"></div>
</body>
</html>